ConfigureDeck & EditDeck user interfaces

`./preview ConfigureDeckView`
`./preview EditDeckView`

Signed-off-by: kernelkind <kernelkind@gmail.com>

src/deck_state.rs

@@ -0,0 +1,65 @@
+use crate::{app_style::emoji_font_family, decks::Deck};
+
+/// State for UI creating/editing deck
+pub struct DeckState {
+    pub deck_name: String,
+    pub selected_glyph: Option<char>,
+    pub deleting: bool,
+    pub selecting_glyph: bool,
+    pub warn_no_title: bool,
+    pub warn_no_icon: bool,
+    glyph_options: Option<Vec<char>>,
+}
+
+impl DeckState {
+    pub fn load(&mut self, deck: &Deck) {
+        self.deck_name = deck.name.clone();
+        self.selected_glyph = Some(deck.icon);
+    }
+
+    pub fn from_deck(deck: &Deck) -> Self {
+        let deck_name = deck.name.clone();
+        let selected_glyph = Some(deck.icon);
+        Self {
+            deck_name,
+            selected_glyph,
+            ..Default::default()
+        }
+    }
+
+    pub fn clear(&mut self) {
+        *self = Default::default();
+    }
+
+    pub fn get_glyph_options(&mut self, ui: &egui::Ui) -> &Vec<char> {
+        self.glyph_options
+            .get_or_insert_with(|| available_characters(ui, emoji_font_family()))
+    }
+}
+
+impl Default for DeckState {
+    fn default() -> Self {
+        Self {
+            deck_name: Default::default(),
+            selected_glyph: Default::default(),
+            deleting: Default::default(),
+            selecting_glyph: true,
+            warn_no_icon: Default::default(),
+            warn_no_title: Default::default(),
+            glyph_options: Default::default(),
+        }
+    }
+}
+
+fn available_characters(ui: &egui::Ui, family: egui::FontFamily) -> Vec<char> {
+    ui.fonts(|f| {
+        f.lock()
+            .fonts
+            .font(&egui::FontId::new(10.0, family)) // size is arbitrary for getting the characters
+            .characters()
+            .iter()
+            .filter(|chr| !chr.is_whitespace() && !chr.is_ascii_control())
+            .copied()
+            .collect()
+    })
+}